1 /* 2 * linux/arch/arm/kernel/devtree.c 3 * 4 * Copyright (C) 2009 Canonical Ltd. <jeremy.kerr@canonical.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 as 8 * published by the Free Software Foundation. 9 */ 10 11 #include <linux/init.h> 12 #include <linux/export.h> 13 #include <linux/errno.h> 14 #include <linux/types.h> 15 #include <linux/bootmem.h> 16 #include <linux/memblock.h> 17 #include <linux/of.h> 18 #include <linux/of_fdt.h> 19 #include <linux/of_irq.h> 20 #include <linux/of_platform.h> 21 #include <linux/smp.h> 22 23 #include <asm/cputype.h> 24 #include <asm/setup.h> 25 #include <asm/page.h> 26 #include <asm/smp_plat.h> 27 #include <asm/mach/arch.h> 28 #include <asm/mach-types.h> 29 30 void __init early_init_dt_add_memory_arch(u64 base, u64 size) 31 { 32 arm_add_memory(base, size); 33 } 34 35 void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align) 36 { 37 return memblock_virt_alloc(size, align); 38 } 39 40 void __init arm_dt_memblock_reserve(void) 41 { 42 u64 *reserve_map, base, size; 43 44 if (!initial_boot_params) 45 return; 46 47 /* Reserve the dtb region */ 48 memblock_reserve(virt_to_phys(initial_boot_params), 49 be32_to_cpu(initial_boot_params->totalsize)); 50 51 /* 52 * Process the reserve map. This will probably overlap the initrd 53 * and dtb locations which are already reserved, but overlaping 54 * doesn't hurt anything 55 */ 56 reserve_map = ((void*)initial_boot_params) + 57 be32_to_cpu(initial_boot_params->off_mem_rsvmap); 58 while (1) { 59 base = be64_to_cpup(reserve_map++); 60 size = be64_to_cpup(reserve_map++); 61 if (!size) 62 break; 63 memblock_reserve(base, size); 64 } 65 } 66 67 #ifdef CONFIG_SMP 68 extern struct of_cpu_method __cpu_method_of_table_begin[]; 69 extern struct of_cpu_method __cpu_method_of_table_end[]; 70 71 static int __init set_smp_ops_by_method(struct device_node *node) 72 { 73 const char *method; 74 struct of_cpu_method *m = __cpu_method_of_table_begin; 75 76 if (of_property_read_string(node, "enable-method", &method)) 77 return 0; 78 79 for (; m < __cpu_method_of_table_end; m++) 80 if (!strcmp(m->method, method)) { 81 smp_set_ops(m->ops); 82 return 1; 83 } 84 85 return 0; 86 } 87 #else 88 static inline int set_smp_ops_by_method(struct device_node *node) 89 { 90 return 1; 91 } 92 #endif 93 94 95 /* 96 * arm_dt_init_cpu_maps - Function retrieves cpu nodes from the device tree 97 * and builds the cpu logical map array containing MPIDR values related to 98 * logical cpus 99 * 100 * Updates the cpu possible mask with the number of parsed cpu nodes 101 */ 102 void __init arm_dt_init_cpu_maps(void) 103 { 104 /* 105 * Temp logical map is initialized with UINT_MAX values that are 106 * considered invalid logical map entries since the logical map must 107 * contain a list of MPIDR[23:0] values where MPIDR[31:24] must 108 * read as 0. 109 */ 110 struct device_node *cpu, *cpus; 111 int found_method = 0; 112 u32 i, j, cpuidx = 1; 113 u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0; 114 115 u32 tmp_map[NR_CPUS] = { [0 ... NR_CPUS-1] = MPIDR_INVALID }; 116 bool bootcpu_valid = false; 117 cpus = of_find_node_by_path("/cpus"); 118 119 if (!cpus) 120 return; 121 122 for_each_child_of_node(cpus, cpu) { 123 u32 hwid; 124 125 if (of_node_cmp(cpu->type, "cpu")) 126 continue; 127 128 pr_debug(" * %s...\n", cpu->full_name); 129 /* 130 * A device tree containing CPU nodes with missing "reg" 131 * properties is considered invalid to build the 132 * cpu_logical_map. 133 */ 134 if (of_property_read_u32(cpu, "reg", &hwid)) { 135 pr_debug(" * %s missing reg property\n", 136 cpu->full_name); 137 return; 138 } 139 140 /* 141 * 8 MSBs must be set to 0 in the DT since the reg property 142 * defines the MPIDR[23:0]. 143 */ 144 if (hwid & ~MPIDR_HWID_BITMASK) 145 return; 146 147 /* 148 * Duplicate MPIDRs are a recipe for disaster. 149 * Scan all initialized entries and check for 150 * duplicates. If any is found just bail out. 151 * temp values were initialized to UINT_MAX 152 * to avoid matching valid MPIDR[23:0] values. 153 */ 154 for (j = 0; j < cpuidx; j++) 155 if (WARN(tmp_map[j] == hwid, "Duplicate /cpu reg " 156 "properties in the DT\n")) 157 return; 158 159 /* 160 * Build a stashed array of MPIDR values. Numbering scheme 161 * requires that if detected the boot CPU must be assigned 162 * logical id 0. Other CPUs get sequential indexes starting 163 * from 1. If a CPU node with a reg property matching the 164 * boot CPU MPIDR is detected, this is recorded so that the 165 * logical map built from DT is validated and can be used 166 * to override the map created in smp_setup_processor_id(). 167 */ 168 if (hwid == mpidr) { 169 i = 0; 170 bootcpu_valid = true; 171 } else { 172 i = cpuidx++; 173 } 174 175 if (WARN(cpuidx > nr_cpu_ids, "DT /cpu %u nodes greater than " 176 "max cores %u, capping them\n", 177 cpuidx, nr_cpu_ids)) { 178 cpuidx = nr_cpu_ids; 179 break; 180 } 181 182 tmp_map[i] = hwid; 183 184 if (!found_method) 185 found_method = set_smp_ops_by_method(cpu); 186 } 187 188 /* 189 * Fallback to an enable-method in the cpus node if nothing found in 190 * a cpu node. 191 */ 192 if (!found_method) 193 set_smp_ops_by_method(cpus); 194 195 if (!bootcpu_valid) { 196 pr_warn("DT missing boot CPU MPIDR[23:0], fall back to default cpu_logical_map\n"); 197 return; 198 } 199 200 /* 201 * Since the boot CPU node contains proper data, and all nodes have 202 * a reg property, the DT CPU list can be considered valid and the 203 * logical map created in smp_setup_processor_id() can be overridden 204 */ 205 for (i = 0; i < cpuidx; i++) { 206 set_cpu_possible(i, true); 207 cpu_logical_map(i) = tmp_map[i]; 208 pr_debug("cpu logical map 0x%x\n", cpu_logical_map(i)); 209 } 210 } 211 212 bool arch_match_cpu_phys_id(int cpu, u64 phys_id) 213 { 214 return phys_id == cpu_logical_map(cpu); 215 } 216 217 static const void * __init arch_get_next_mach(const char *const **match) 218 { 219 static const struct machine_desc *mdesc = __arch_info_begin; 220 const struct machine_desc *m = mdesc; 221 222 if (m >= __arch_info_end) 223 return NULL; 224 225 mdesc++; 226 *match = m->dt_compat; 227 return m; 228 } 229 230 /** 231 * setup_machine_fdt - Machine setup when an dtb was passed to the kernel 232 * @dt_phys: physical address of dt blob 233 * 234 * If a dtb was passed to the kernel in r2, then use it to choose the 235 * correct machine_desc and to setup the system. 236 */ 237 const struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys) 238 { 239 const struct machine_desc *mdesc, *mdesc_best = NULL; 240 241 #ifdef CONFIG_ARCH_MULTIPLATFORM 242 DT_MACHINE_START(GENERIC_DT, "Generic DT based system") 243 MACHINE_END 244 245 mdesc_best = &__mach_desc_GENERIC_DT; 246 #endif 247 248 if (!dt_phys || !early_init_dt_scan(phys_to_virt(dt_phys))) 249 return NULL; 250 251 mdesc = of_flat_dt_match_machine(mdesc_best, arch_get_next_mach); 252 253 if (!mdesc) { 254 const char *prop; 255 long size; 256 unsigned long dt_root; 257 258 early_print("\nError: unrecognized/unsupported " 259 "device tree compatible list:\n[ "); 260 261 dt_root = of_get_flat_dt_root(); 262 prop = of_get_flat_dt_prop(dt_root, "compatible", &size); 263 while (size > 0) { 264 early_print("'%s' ", prop); 265 size -= strlen(prop) + 1; 266 prop += strlen(prop) + 1; 267 } 268 early_print("]\n\n"); 269 270 dump_machine_table(); /* does not return */ 271 } 272 273 /* Change machine number to match the mdesc we're using */ 274 __machine_arch_type = mdesc->nr; 275 276 return mdesc; 277 } 278